Fix CtsVirtualDevicesAppLaunchTestCases#RecentTasksTest

Removes the test activity when the virtual display is removed
if the DisplayInfo#removeMode is REMOVE_MODE_DESTROY_CONTENT
and the display-window-settings is undefined.

Bug: 359902777
Test: atest RecentTasksTest
Flag: EXEMPT bugfix
Change-Id: I2aaf2684777f8f950a157922104a5ae2024d58b0